Roof question

[Bim Man]

roofs are my achiles that said, i am having trouble with this roof. on the right side i can not get them to join properly. i do not want to raise the plate height of the front gables, since that would make them higher that the garage side. also can this be made as 1 roof or does it need to be made with multiple roofs joined together. i have attached a floor plan and a very rough sketch at what i am trying to achieve.

more info:

9:12 on the front gables and 6:12 side gables and 8" overhang on all sides

thanks for the help in advance

Pete

[Bim Man]

ok they did not attach lets try it again

[aaronrumple]

Basically waht you are asking for will result in differing fascia depths or differing corner of roof heights if the same plate height is used for both slopes - and hence they won't join. You would have to vary the location the heal hits the plate slightly in order to have a common corner of roof. The you'll need a different cut on the end of the rafters to get the same soffit and fascia height. (Not really a Revit problem. More of a carpentry problem.)

With that said look at the example. See the drafting view for an illustration of the above problem. You can also move the 9/12 pitch up in section to align the corners of roofs - but then you'll need to figure out what cuts you'll need on the rafters.

[Roger Evans]

Not an answer to the specific problem here but I need to vent a bit

I get confused with the American Imperial methods of working roofs & cannot easily visualise gradients eg 9:12 etc.
So sometimes picking up info from threads here does not always lead to clarification.

Personally I always use degrees ~ and on a side note it is very rare for me to alter angles of roof pitches on the same roof (or building) ~ especially when dealing with valley junctions & hips etc

ie My Golden Rule is If you maintain the same angle throughout you will get junctions at 45 deg on plan ~ any deviation from a standard pitch throws this out and leads to problems with junctions & fit of materials. (Not recommended).

Thank you & sorry for the interruption

[Allen Lacy]

Not an answer to the specific problem here but I need to vent a bit

I get confused with the American Imperial methods of working roofs & cannot easily visualise gradients eg 9:12 etc.
So sometimes picking up info from threads here does not always lead to clarification.

Personally I always use degrees ~ and on a side note it is very rare for me to alter angles of roof pitches on the same roof (or building) ~ especially when dealing with valley junctions & hips etc

ie My Golden Rule is If you maintain the same angle throughout you will get junctions at 45 deg on plan ~ any deviation from a standard pitch throws this out and leads to problems with junctions & fit of materials. (Not recommended).

Thank you & sorry for the interruption Roger, I'm curious. How do the builders deal with angles when constructing roof in the field? I know the American method uses a framing square and the rafters are laid out from it by going horizontally 12 inches (or units) and vertically "X" inches (or units). This seems straight forward to me. Just want to learn how it's done elsewhere. Thanks.

[Roger Evans]

Truthfully I haven't seen a Carpenter use a "square" for years ~ seems to be a lost art
& yes I do see the advantages on site for this method once you get into the mindset for laying it out ~ its just we don't specify roofs by this method but by clean angles & generally in 5 Deg increments. Normally I see plumb & seat cuts marked out with bevels

We used to use the same roof methodology 9:12 etc with variations eg locally in Gower it was 9:12 plus a foot (the logic of this escapes me)

Gradients are used for ramps /drainage / flat roofs / crossfalls but are not the common parlance for pitched roofs

I am trying to get a handle on your methods & The diagram was drawn up on a grid which hasn't showed itself in the Jpeg ~ but you can see the angles produced
Q? If the 9:12 is a 3/4/5 triangle what are the other ratios of common use gradients?

[adegnan]

4/12 is a common pitch for Prairie-style architecture. Also common to 1950's - 1980's plain-jane houses (ranch, raised ranch, simple 2-story etc.). It is also the last pitch where a carpenter can set his tools on the roof without them sliding down.

5/12 is now the new 4/12 and is commonly considered the minimum roof pitch.

6/12 is also common and is the last easily walkable roof pitch. Anything above that pitch really begins to require additional staging & safety equipment (although OSHA views things more strictly already!)

I see enough 7/12, 8/12, and 10/12 also depending on the design.

Is that what you were wondering?

[SkiSouth]

ok they did not attach lets try it again

See if this helps. It was something to do. You've probably already worked it out...

[Bim Man]

hey everbody,

thanks for the leads i have been snowed in for 4 days no phone line or power to check out the reponses. just wanted to let you all know i was not putting anyone off. the last few days have been a burr not a blurr.

thanks again

pete

[Bim Man]

arron & ski,

how did you guys get the right side roof line to split so there is a gable over the front room and the 6:12 front to back. when i try i get the whole side as a hip. the front to back 6:12 gets follows the 9:12 with the front gable. i have 2 seperate lines there be they must be reacting as one line.

Pete

[SkiSouth]

arron & ski,

how did you guys get the right side roof line to split so there is a gable over the front room and the 6:12 front to back. when i try i get the whole side as a hip. the front to back 6:12 gets follows the 9:12 with the front gable. i have 2 seperate lines there be they must be reacting as one line.

Pete

Back 6 on 12 is one roof
front gables are separate roof. Then use join.
Edit the roof I posted and this will become evident.

[Bim Man]

the main body roof we will calll the 6:12 and the roof to the right which is over the bedrooms all are 1 roof from what i can make out. to unjoin them i would check join rrof tool and click the roof to be unjoined this works for the garage area and your gable on the rear. i do not see how the other sections are joined. unless you drew 2 roof plans in sketch mode and then joined them. is that correct,

[Bim Man]

ok i am at a loss as to how they are joined once i find out i'll most likly hit myself for asking something i already knew but already forgot.

[SkiSouth]

the main body roof we will calll the 6:12 and the roof to the right which is over the bedrooms all are 1 roof from what i can make out. to unjoin them i would check join rrof tool and click the roof to be unjoined this works for the garage area and your gable on the rear. i do not see how the other sections are joined. unless you drew 2 roof plans in sketch mode and then joined them. is that correct,

The roof I posted is actually three roofs, all joined using the roof join/unjoin tool. (This tool is listed right under the edit Wall Joins in the Tools pulldown) Select the edge of the roof towards the roof you wish to join (it will highlight) Then the face of the roof you wish to join that roof to. Revit will do the rest (if the join is possible).

[Bim Man]

gotcha, then my question is on the main roof how did you get the roof to break at a 6:12 gable on the right side and have a 9:12 over the bedrooms that is where i keep getting the whole side as a hip

[SkiSouth]

gotcha, then my question is on the main roof how did you get the roof to break at a 6:12 gable on the right side and have a 9:12 over the bedrooms that is where i keep getting the whole side as a hip

Its more simple than you'd think. Simply use the split tool when you sketch the roof. The break should occur to EXACTLY align with the opposite side of the gable. Then define the gable portion as a "no slope" line, the bedroom portion as having 9 on 12. Edit the roof and pick on the right most line. You'll find it's actually two lines, one with slope, one without.

[Bim Man]

i thought i did that i will try agian and be more careful at what i do to see if it works

thanks

[Bim Man]

well in my project i can not do it. so started from a cleam template file and tried it that way and it worked. so that tells me that tomorrow i need to redo my roof on my model. is there any difference in pick walls or sketching lines. in my model project the roof was done by picking walls. i kept getting eave hgts do not match errors. but on the dwg i trace over i did not have that problem i was able to get the whole thing in 1 piece. all looks good except for the area by the garage seervice door i was wanting the 9:12 to run back along side the house and 6:12 to die into the 9:12 ratghe than the offest straight up vault that i got. i will work on that tomorrow. take a look and see what you think.

[SkiSouth]

Look at your back wall. If you were trying to get your existing model to frame like the model posted then note that there are TWO eave heights on the back wall. The wall at the study and owner's bath would be taller, thus the eave height higher. I think Revit was trying to do what you wanted but could not without a resolution of this condition. It might have worked if you did not define the slope over the higher wall along that side. Not sure though.

As far as the area over the garage, I think it would be simplier just to make a second roof over the garage and join them. Than would create the condition you want.

Well done.

[Bim Man]

to get the roof higher on the owner's bath side i set the offset from roof height at 1'-10 11/16". simulating a raised heel truss. i was getting the align eave errors on the aeras where the 6:12 and 9:12 where making valleys..

i do think you right about the garage roof it will give me the condition i want. but i was hoping to get it in 1 piece.

anything that would affect the way the roof is done through pick walls or lines?

Pete

[Bim Man]

there must be something with the pick walls i started over and it was doing the same thing. but when i place the roof lines bt drawing them in and offseting then rather than setting an over hang all went well and work great. can i get an explanation as to the difference from someone so i can understsnd the difference in the t wo ways of doing roof.

Pete

[gravelin]

Maybe this picture can help you
one important consequence of this choice : pick or sketch is how the roof is placed and articulate
In this picture : at left the linewas sketched, right it is picked

[Bim Man]

that makes sense now. it appears the pick some how associates the over hang with the wall and bearring level. where draw places the ends of the joists at the bearing level. that is exactly what i got when i drew them and i then lowered the roof to where the truss would actually sit. thanks for your diagram.

Pete